1. Technical Field
The present invention relates to a test apparatus and a test method.
2. Related Art
As a conventional test apparatus for testing a device under test, an apparatus is known that includes a comparator for comparing the signal level of a signal under measurement output by the device under test to a prescribed reference level, as shown in Patent Document 1, for example.
Patent Document 1: Japanese Patent Application Publication No. H11-237454
The conventional test apparatus evaluates the signal under measurement based on 1-bit information output by the comparator. Therefore, the apparatus is sensitive to noise, timing jitter, or the like, and it is difficult to improve the measurement accuracy.
For example, the conventional test apparatus changes the timing of a strobe signal input to the comparator and detects the timing at which the logic value of the signal under measurement transitions. However, when noise, timing jitter, or the like is superimposed on the signal under measurement, incorrect detection of the logic value of the signal under measurement becomes more likely, and an incorrect timing for the transition of the logic value is detected.